ABSTRACT
Engineers appeared as designers and builders of irrigation systems, fortifications, public buildings and great tombs. In the sarsen ring, the first Stonehenge builders created a circular structure where the sum of the vertical forces acting on the beams are in equilibrium or zero. The ditch is inside the bank, such as at Stonehenge’s larger neighbor, Avebury, which signifies a non-military function. The Neolithic marked the end of the glacial age — a hard and difficult time — with vast areas being uninhabitable for plants, animals, and humans. The development of primitive agriculture is one major definitive characteristic of the Neolithic Period. In the late Neolithic and early Chalcolithic Periods, a simple earthen structure was constructed on Salisbury Plain. With the trilithons, the lateral support of the adjacent lintels have been foregone to create a construction which contrasts massiveness with free-standing form.
